Being a Mobil 1 user I prefer that brand for features, value and availability throughout the country.  Amsoil and Shell Rotella T synthetic seem like good alternatives, but I don't like Amsoils marketing system and Rotella T synthetic is NOT a true synthetic, rather a highly processed mineral based oil from group III, not the synthetic groups IV and V.  

I guess you pays your money and makes your choices, but the idea of motorcycle specific oils leaves me cold and the extra expense seems unjustified too.

My two bits worth.

Ray Nielsen, in Minneapolis and a Mobil 1 user in everything motorized that I own, since 1983. 

Some cars come from the facory now with synthetic oil in them and it is recommended to keep using it.  Not sure about motorcycles but I started using Rotella on my first oil change and bike has over 70,000 trouble free miles on it now.  Not sure where the opinion came from to use dino oil for awhile before switching to the synthetic but most people feel better going that way. 

"Life's journey is not arriving at the gate safely in a well perserved body, but rather to skid-in-sideways, totally worn out, shouting...holy *...what a ride!"

Some Covettes, Aston-Martins, Porsches and BMWs come with Mobil 1 from the factory.  Porsche says you must use it to maintain the warranty and in MN that means the dealers MJST furnish it free under the Magnuson-Moss warranty act, a federal statute.  They still charge for the service though, about $90 for an oil and filter change according to one Porsche owner I see regularly.

I've used Mobil 1, 15W-50 in my motorcycles since 1983 going through at least three formulations over the years -- all with good results.  No clutch slippage and no lubrication problems.  Most of my bikes accummulate high mileage before being sold, and some have gone to friends so I've been able to track history.

In the cars I've used both 5W-30 automotive and 5W-40 Truck & SUV oil.  The Truck & SUV oil carries the highest ratings for BOTH gasoline and diesel engines (SM and CI-4+ respectively). 

Oil analysis by Blackstone Laboratories confirms that the oil is still functioning well after 7500 - 9000 mile intervals in the cars and 5000-6000 mile intervals in the bikes.  One recent analysis even showed evidence of too much silicon in the oil, traceable to a torn air filter element.  A sample is on its way to them now after another 7500 miles with a new, factory air cleaner element in place.  The FRAM replacement had deformed when the cover was installed, probably due to faulty molding of the rubber body!  The Hyundai filter literally dropped into place and the cover went on effortlessly. 

While more expensive than some other oils, the peace of mind is of some value to me, along with superior cold weather start up lubrication AND hot weather protection of synthetic oils.

Ray Nielsen, in Minneapolis.

As I've stated quite often here, I still continue to use fossil in my car, pickup and motorhome (10-30) and 20-50 in my H-D...and have never had any oil related motor problems in my 40+ years of driving/riding.  Oil gets changed EVERYWHERE every 3000 miles...and I'll continue to use fossil until it becomes just as expensive as syn.

Shouldn't be too long, now......